Marc Andreessen writes a blog that I never read. That proved a negligible obstacle, however, in discovering this two-part series he wrote on career planning. In the disclaimers, he is careful to point out that his advice is intended for "high-potential people who want to excel throughout their careers and make a significant impact on their fields and the world. These posts are not appropriate for people for whom work/life balance is a high priority or for whom lifestyle is particularly important." In any case, I think his advice is similar to the advice I would give my progeny someday should I have any (perish the thought).
Following are some highlights:

The first rule of career planning is to not plan your career. The world is always changing and plans become outdated as soon as they are formed. Instead, focus on developing skills and pursuing available opportunities, whatever they may be.

Careers should be thought of as a portfolio comprised of jobs, roles, and opportunities over a fifty-year time horizon. A good career will have a good mix of the three, with the appropriate balance of risk and return considered over the entire life of the portfolio.

Majoring in something that you are "passionate about" in college is a waste of time. Instead, major in a technical subject (e.g. engineering, natural sciences, mathematics, economics) that will give you concrete skills. You can pursue your passion after you graduate.

Graduate degrees are usually overrated if you have a useful undergraduate degree. If you don't have a useful undergraduate degree, then you should get a useful graduate degree (such as an MBA). Even if you do have a useful undergraduate background, an MBA on top of an undergraduate math or engineering background is invaluable, as is an MBA/law degree combination. PhDs are not useful.

What really interested me was Andreessen's thoughts on education. Even though Andreessen's advice is directed to those who want to be über-successful in their particular field, I think it's good advice for virtually anyone entering college regardless of what life they wish to lead upon graduation. To me, higher education's main benefit is not is being taught what to think, but how to think. Technically-oriented degrees accomplish this well. English and History degrees do not. Finding a program that develops critical reasoning and rigorous thinking will allow one to excel far further and faster in any particular field than one which encourages rote memory and/or baseless discussion.

If I could go back and do my four years over again, I would focus on taking as many classes in math, statistics, and economics as I could. I wouldn't particularly enjoy the math or stats classes, mind you, but I know my analytical skills would be far better than they are now.

And then of course there's the fact that mathematicians, statisticians, and economists all do it with models.